A mirror with a flat surface is a plane mirror that reflects light and produces a virtual image without the interference of an inward or outward curve is called a plane mirror.

### Solution

As per the figure

Let us assume the two incident angles

∠BAD=x

∠ABD=y

We observe that

⇒∠OBA=90−y

∠OAB=90−x

ΔOAB=>θ+90−y+90−1=180

⇒x+y=θ

Total deviation is 2(90−x)+2(90−y)

=360−2(x+y)

=360−2θ

**Answer**

The deviation of incident ray =360−2θ